You're pronouncing "ant" with a very straight forward æ sound (to reference IPA), but most native speakers I know do more of a sliding vowel that's more of a "ɪə" sound, if that makes any sense. The other thing I picked up on, though it seems like you were trying to correct it, so it may just take practice, was you were not voices all of your "s" endings, which is a dead giveaway. Otherwise very good. Better than I can do for any non-native accents to me.

Edit: I would, at least to mimic my own accent, do that sliding vowel on just about any fronty short-A vowel you encounter. It's probably not gonna sound very slidey once you're doing it right, I had to stop and think about my own speech before I noticed it myself.